Effect of antimony concentration on optical, electrical and structuralproperties of copper antimony sulphide thin films deposited by spray pyrolysis technique

Copper antimony sulphide (CuSbS2) is a semiconductor with narrow band gap and a potential absorber material for applications in various optoelectronic devices like infrared detectors and solar cells. In this paper, CuSbS2 thin films were deposited by spray pyrolysis technique on glass substrates at a temperature of 3000 ℃, using cupric chloride, antimony chloride, and thiourea as precursors. The samples were prepared by varying the antimony concentration (0.1M, 0.15M, and 0.2M) at a pressure of 3.5 bar and a solution flow rate of 2 ml/min for 5 minutes, while the precursor solutions of Cu:S molar ratio (0.1:0.2) was maintained. Elemental, morphological, optical, and structural characterization of these films was done from data obtained from energy dispersive X-ray fluorescence (EDXRF), UV-VIS spectrophotometer, scanning electron microscope (SEM) and X-Ray diffraction (XRD) respectively. The prepared thin films were polycrystalline with a preferential peak at (111).  Electrical properties of the thin films were obtained by simulating the UV-VIS spectra in SCOUT software using the Drude and Kim oscillator model. Deposited films have a band gap range of 1.84 – 1.98 eV, conductivity range of 199.59 – 204.67 Ω-1cm-1, and carrier concentration range of 1.12×1019 - 1.27×1019  cm-3.